diff options
| -rw-r--r-- | block.c | 23 | ||||
| -rw-r--r-- | include/block/block_int.h | 23 |
2 files changed, 34 insertions, 12 deletions
@@ -305,6 +305,7 @@ BlockDriverState *bdrv_new(const char *device_name) } bdrv_iostatus_disable(bs); notifier_list_init(&bs->close_notifiers); + notifier_with_return_list_init(&bs->before_write_notifiers); return bs; } @@ -1840,16 +1841,6 @@ int bdrv_commit_all(void) return 0; } -struct BdrvTrackedRequest { - BlockDriverState *bs; - int64_t sector_num; - int nb_sectors; - bool is_write; - QLIST_ENTRY(BdrvTrackedRequest) list; - Coroutine *co; /* owner, used for deadlock detection */ - CoQueue wait_queue; /* coroutines blocked on this request */ -}; - /** * Remove an active request from the tracked requests list * @@ -2620,7 +2611,11 @@ static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs, tracked_request_begin(&req, bs, sector_num, nb_sectors, true); - if (flags & BDRV_REQ_ZERO_WRITE) { + ret = notifier_with_return_list_notify(&bs->before_write_notifiers, &req); + + if (ret < 0) { + /* Do nothing, write notifier decided to fail this request */ + } else if (flags & BDRV_REQ_ZERO_WRITE) { ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors); } else { ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov); @@ -4581,3 +4576,9 @@ AioContext *bdrv_get_aio_context(BlockDriverState *bs) /* Currently BlockDriverState always uses the main loop AioContext */ return qemu_get_aio_context(); } + +void bdrv_add_before_write_notifier(BlockDriverState *bs, + NotifierWithReturn *notifier) +{ + notifier_with_return_list_add(&bs->before_write_notifiers, notifier); +} diff --git a/include/block/block_int.h b/include/block/block_int.h index ba52247c1a..2d009556b0 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -59,7 +59,16 @@ #define BLOCK_OPT_LAZY_REFCOUNTS "lazy_refcounts" #define BLOCK_OPT_ADAPTER_TYPE "adapter_type" -typedef struct BdrvTrackedRequest BdrvTrackedRequest; +typedef struct BdrvTrackedRequest { + BlockDriverState *bs; + int64_t sector_num; + int nb_sectors; + bool is_write; + QLIST_ENTRY(BdrvTrackedRequest) list; + Coroutine *co; /* owner, used for deadlock detection */ + CoQueue wait_queue; /* coroutines blocked on this request */ +} BdrvTrackedRequest; + typedef struct BlockIOLimit { int64_t bps[3]; @@ -248,6 +257,9 @@ struct BlockDriverState { NotifierList close_notifiers; + /* Callback before write request is processed */ + NotifierWithReturnList before_write_notifiers; + /* number of in-flight copy-on-read requests */ unsigned int copy_on_read_in_flight; @@ -299,6 +311,15 @@ void bdrv_set_io_limits(BlockDriverState *bs, BlockIOLimit *io_limits); /** + * bdrv_add_before_write_notifier: + * + * Register a callback that is invoked before write requests are processed but + * after any throttling or waiting for overlapping requests. + */ +void bdrv_add_before_write_notifier(BlockDriverState *bs, + NotifierWithReturn *notifier); + +/** * bdrv_get_aio_context: * * Returns: the currently bound #AioContext |